This invention relates to an adaptive-quantizing apparatus and method for high-resolution television, and particularly an adaptive-quantizing apparatus and method with quantization spacing being adjusted in accordance with the human visual system.
Generally, high definition television involves coding and decoding of digitized picture signals. The picture data in a digital form is superior to the analog form in effective storage and noise control and processing. Digitization of the picture data means generation of a tremendous amount of data. For instance, NTSC television signals are to be digitized to data of about 114 Mbp. If a color picture frame of 512 by 512 pixels with 8-bit color components for red, green and blue is transmitted at 2400 bps, it will take as long as the order of 44 minutes. This makes the compression technology particularly critical for efficiently storing and transmitting picture data.
There are two kinds of compression coding techniques, one for moving pictures eliminating overlappings between time-spaced frames, and another for still pictures eliminating spatial overlappings.